var b = 'boy';
console.log(b);
function fighting() {
  console.log(a);
  console.log(c);
  if (a === 'apple') {
    a = 'Alice';
  }
  else {
    a = 'Ada';
  }
  console.log(a);
  var a = 'Andy';
  middle();
  function middle () {
    console.log(c++);
    var c = 100;
    console.log(++c);
    small();
    function small() {
      console.log(a);
    }
  }
  var c = a = 88;
  function bottom () {
    console.log(this.b);
    // 这里如果是 NodeJs 返回 undefined，如果是 浏览器 Console，返回 boy
    b = 'baby';
    console.log(b);
  }
  bottom();
}
fighting();
console.log(b);